The Aktiv™ Preclean (“APC”) chamber is a significant feature of the Endura CuBS (copper barrier/seed) system available from Applied Materials, Inc., and provides a benign and efficient cleaning process for removal of polymeric residues and reaction of copper oxide (“CuO”) for copper low-k interconnect process schemes for 28 nm generation and below nodes. In particular, APC is designed to effectively remove polymeric residues and reduce CuO deposits while preserving the integrity of porous low and ultra-low k inter-level dielectric (“ILD”) films.
While APC is an essential process for 28 nm generation and below nodes, there is currently no suitable methodology for monitoring the CuO etch rate, and therefore monitoring the efficacy, thereof.
Therefore, what is needed is an acceptable thermal oxide etch rate monitor for an APC process.